/**
* @file
* Ethernet Interface for standalone applications (without RTOS) - works only for 
* ethernet polling mode (polling for ethernet frame reception)
*
*/

/*
* Copyright (c) 2001-2004 Swedish Institute of Computer Science.
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without modification,
* are permitted provided that the following conditions are met:
*
* 1. Redistributions of source code must retain the above copyright notice,
*    this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright notice,
*    this list of conditions and the following disclaimer in the documentation
*    and/or other materials provided with the distribution.
* 3. The name of the author may not be used to endorse or promote products
*    derived from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED
* WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
* MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT
* SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
* EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT
* OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
* IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY
* OF SUCH DAMAGE.
*
* This file is part of the lwIP TCP/IP stack.
*
* Author: Adam Dunkels <adam@sics.se>
*
*/

#include "lwip/opt.h"
#include "lwip/mem.h"
#include "netif/etharp.h"
#include "ethernetif.h"
#include "stm32f429_eth.h"
#include "netconf.h"
#include <string.h>

#include "los_base.h"
#include "los_task.ph"
#include "los_hwi.h"

/* Network interface name */
#define IFNAME0 'b'
#define IFNAME1 'h'

#define MAC_ADDR        "\xF4\x83\xE1\x01\x01\x02"

/* Ethernet Rx & Tx DMA Descriptors */
extern ETH_DMADESCTypeDef  DMARxDscrTab[ETH_RXBUFNB], DMATxDscrTab[ETH_TXBUFNB];

/* Ethernet Driver Receive buffers  */
extern uint8_t Rx_Buff[ETH_RXBUFNB][ETH_RX_BUF_SIZE]; 

/* Ethernet Driver Transmit buffers */
extern uint8_t Tx_Buff[ETH_TXBUFNB][ETH_TX_BUF_SIZE]; 

/* Global pointers to track current transmit and receive descriptors */
extern ETH_DMADESCTypeDef  *DMATxDescToSet;
extern ETH_DMADESCTypeDef  *DMARxDescToGet;

/* Global pointer for last received frame infos */
extern ETH_DMA_Rx_Frame_infos *DMA_RX_FRAME_infos;

extern struct netif gnetif;

static err_t ethernetif_input(void);

static UINT32 g_uwEthnetifInputTaskID;

/**
* In this function, the hardware should be initialized.
* Called from ethernetif_init().
*
* @param netif the already initialized lwip network interface structure
*        for this ethernetif
*/
static void low_level_init(struct netif *netif)
{
    uint32_t uwRet;
    TSK_INIT_PARAM_S stTaskInitParam;
    
#ifdef CHECKSUM_BY_HARDWARE
    int i; 
#endif
    /* set MAC hardware address length */
    netif->hwaddr_len = ETHARP_HWADDR_LEN;
    
    /* set MAC hardware address */
    netif->hwaddr[0] =  MAC_ADDR[0];
    netif->hwaddr[1] =  MAC_ADDR[1];
    netif->hwaddr[2] =  MAC_ADDR[2];
    netif->hwaddr[3] =  MAC_ADDR[3];
    netif->hwaddr[4] =  MAC_ADDR[4];
    netif->hwaddr[5] =  MAC_ADDR[5];
    
    /* initialize MAC address in ethernet MAC */ 
    ETH_MACAddressConfig(ETH_MAC_Address0, netif->hwaddr); 
    
    /* maximum transfer unit */
    netif->mtu = 1500;
    
    /* device capabilities */
    /* don't set NETIF_FLAG_ETHARP if this device is not an ethernet one */
    netif->flags = NETIF_FLAG_BROADCAST | NETIF_FLAG_ETHARP | NETIF_FLAG_LINK_UP;
    
    /* Initialize Tx Descriptors list: Chain Mode */
    ETH_DMATxDescChainInit(DMATxDscrTab, &Tx_Buff[0][0], ETH_TXBUFNB);
    /* Initialize Rx Descriptors list: Chain Mode  */
    ETH_DMARxDescChainInit(DMARxDscrTab, &Rx_Buff[0][0], ETH_RXBUFNB);
    
#ifdef CHECKSUM_BY_HARDWARE
    /* Enable the TCP, UDP and ICMP checksum insertion for the Tx frames */
    for(i=0; i<ETH_TXBUFNB; i++)
    {
        ETH_DMATxDescChecksumInsertionConfig(&DMATxDscrTab[i], ETH_DMATxDesc_ChecksumTCPUDPICMPFull);
    }
#endif
    
    /* Note: TCP, UDP, ICMP checksum checking for received frame are enabled in DMA config */
    
    /* Enable MAC and DMA transmission and reception */
    ETH_Start();
    
    (VOID)memset((void *)(&stTaskInitParam), 0, sizeof(TSK_INIT_PARAM_S));
    stTaskInitParam.pfnTaskEntry = (TSK_ENTRY_FUNC)ethernetif_input;
    stTaskInitParam.uwStackSize = 512;
    stTaskInitParam.pcName = "ethInput";
    stTaskInitParam.usTaskPrio = 10;
    uwRet = LOS_TaskCreate(&g_uwEthnetifInputTaskID, &stTaskInitParam);
    
    if (uwRet != LOS_OK)
    {
        return;
    }
    return;
}

/**
* This function should do the actual transmission of the packet. The packet is
* contained in the pbuf that is passed to the function. This pbuf
* might be chained.
*
* @param netif the lwip network interface structure for this ethernetif
* @param p the MAC packet to send (e.g. IP packet including MAC addresses and type)
* @return ERR_OK if the packet could be sent
*         an err_t value if the packet couldn't be sent
*
* @note Returning ERR_MEM here if a DMA queue of your MAC is full can lead to
*       strange results. You might consider waiting for space in the DMA queue
*       to become availale since the stack doesn't retry to send a packet
*       dropped because of memory failure (except for the TCP timers).
*/

static err_t low_level_output(struct netif *netif, struct pbuf *p)
{
    err_t errval;
    struct pbuf *q;
    u8 *buffer =  (u8 *)(DMATxDescToSet->Buffer1Addr);
    __IO ETH_DMADESCTypeDef *DmaTxDesc;
    uint16_t framelength = 0;
    uint32_t bufferoffset = 0;
    uint32_t byteslefttocopy = 0;
    uint32_t payloadoffset = 0;
    
    DmaTxDesc = DMATxDescToSet;
    bufferoffset = 0;
    
    /* copy frame from pbufs to driver buffers */
    for(q = p; q != NULL; q = q->next)
    {
        /* Is this buffer available? If not, goto error */
        if((DmaTxDesc->Status & ETH_DMATxDesc_OWN) != (u32)RESET)
        {
            errval = ERR_BUF;
            goto error;
        }
        
        /* Get bytes in current lwIP buffer */
        byteslefttocopy = q->len;
        payloadoffset = 0;
        
        /* Check if the length of data to copy is bigger than Tx buffer size*/
        while( (byteslefttocopy + bufferoffset) > ETH_TX_BUF_SIZE )
        {
            /* Copy data to Tx buffer*/
            memcpy( (u8_t*)((u8_t*)buffer + bufferoffset), (u8_t*)((u8_t*)q->payload + payloadoffset), (ETH_TX_BUF_SIZE - bufferoffset) );
            
            /* Point to next descriptor */
            DmaTxDesc = (ETH_DMADESCTypeDef *)(DmaTxDesc->Buffer2NextDescAddr);
            
            /* Check if the buffer is available */
            if((DmaTxDesc->Status & ETH_DMATxDesc_OWN) != (u32)RESET)
            {
                errval = ERR_USE;
                goto error;
            }
            
            buffer = (u8 *)(DmaTxDesc->Buffer1Addr);
            
            byteslefttocopy = byteslefttocopy - (ETH_TX_BUF_SIZE - bufferoffset);
            payloadoffset = payloadoffset + (ETH_TX_BUF_SIZE - bufferoffset);
            framelength = framelength + (ETH_TX_BUF_SIZE - bufferoffset);
            bufferoffset = 0;
        }
        
        /* Copy the remaining bytes */
        memcpy( (u8_t*)((u8_t*)buffer + bufferoffset), (u8_t*)((u8_t*)q->payload + payloadoffset), byteslefttocopy );
        bufferoffset = bufferoffset + byteslefttocopy;
        framelength = framelength + byteslefttocopy;
    }
    
    /* Note: padding and CRC for transmitted frame 
    are automatically inserted by DMA */
    
    /* Prepare transmit descriptors to give to DMA*/ 
    ETH_Prepare_Transmit_Descriptors(framelength);
    
    errval = ERR_OK;
    
error:
    
    /* When Transmit Underflow flag is set, clear it and issue a Transmit Poll Demand to resume transmission */
    if ((ETH->DMASR & ETH_DMASR_TUS) != (uint32_t)RESET)
    {
        /* Clear TUS ETHERNET DMA flag */
        ETH->DMASR = ETH_DMASR_TUS;
        
        /* Resume DMA transmission*/
        ETH->DMATPDR = 0;
    }
    return errval;
}

/**
* Should allocate a pbuf and transfer the bytes of the incoming
* packet from the interface into the pbuf.
*
* @param netif the lwip network interface structure for this ethernetif
* @return a pbuf filled with the received packet (including MAC header)
*         NULL on memory error
*/
static struct pbuf * low_level_input(struct netif *netif)
{
    struct pbuf *p, *q;
    uint32_t len;
    FrameTypeDef frame;
    u8 *buffer;
    __IO ETH_DMADESCTypeDef *DMARxDesc;
    uint32_t bufferoffset = 0;
    uint32_t payloadoffset = 0;
    uint32_t byteslefttocopy = 0;
    uint32_t i=0;  
    
    /* get received frame */
    frame = ETH_Get_Received_Frame();
    
    /* Obtain the size of the packet and put it into the "len" variable. */
    len = frame.length;
    buffer = (u8 *)frame.buffer;
    
    /* We allocate a pbuf chain of pbufs from the Lwip buffer pool */
    p = pbuf_alloc(PBUF_RAW, len, PBUF_POOL);
    
    if (p != NULL)
    {
        DMARxDesc = frame.descriptor;
        bufferoffset = 0;
        for(q = p; q != NULL; q = q->next)
        {
            byteslefttocopy = q->len;
            payloadoffset = 0;
            
            /* Check if the length of bytes to copy in current pbuf is bigger than Rx buffer size*/
            while( (byteslefttocopy + bufferoffset) > ETH_RX_BUF_SIZE )
            {
                /* Copy data to pbuf*/
                memcpy( (u8_t*)((u8_t*)q->payload + payloadoffset), (u8_t*)((u8_t*)buffer + bufferoffset), (ETH_RX_BUF_SIZE - bufferoffset));
                
                /* Point to next descriptor */
                DMARxDesc = (ETH_DMADESCTypeDef *)(DMARxDesc->Buffer2NextDescAddr);
                buffer = (unsigned char *)(DMARxDesc->Buffer1Addr);
                
                byteslefttocopy = byteslefttocopy - (ETH_RX_BUF_SIZE - bufferoffset);
                payloadoffset = payloadoffset + (ETH_RX_BUF_SIZE - bufferoffset);
                bufferoffset = 0;
            }
            /* Copy remaining data in pbuf */
            memcpy( (u8_t*)((u8_t*)q->payload + payloadoffset), (u8_t*)((u8_t*)buffer + bufferoffset), byteslefttocopy);
            bufferoffset = bufferoffset + byteslefttocopy;
        }
    }
    
    /* Release descriptors to DMA */
    DMARxDesc =frame.descriptor;
    
    /* Set Own bit in Rx descriptors: gives the buffers back to DMA */
    for (i=0; i<DMA_RX_FRAME_infos->Seg_Count; i++)
    {  
        DMARxDesc->Status = ETH_DMARxDesc_OWN;
        DMARxDesc = (ETH_DMADESCTypeDef *)(DMARxDesc->Buffer2NextDescAddr);
    }
    
    /* Clear Segment_Count */
    DMA_RX_FRAME_infos->Seg_Count =0;
    
    /* When Rx Buffer unavailable flag is set: clear it and resume reception */
    if ((ETH->DMASR & ETH_DMASR_RBUS) != (u32)RESET)  
    {
        /* Clear RBUS ETHERNET DMA flag */
        ETH->DMASR = ETH_DMASR_RBUS;
        /* Resume DMA reception */
        ETH->DMARPDR = 0;
    }
    return p;
}

/**
* This function should be called when a packet is ready to be read
* from the interface. It uses the function low_level_input() that
* should handle the actual reception of bytes from the network
* interface. Then the type of the received packet is determined and
* the appropriate input function is called.
*
* @param netif the lwip network interface structure for this ethernetif
*/
static err_t ethernetif_input(void)
{
    err_t err;
    struct netif *netif = &gnetif;
    struct pbuf *p;

    while(1)
    {
        LOS_TaskDelay(1);
        
        /* check if any packet received */
        if (ETH_CheckFrameReceived())
        {
            /* move received packet into a new pbuf */
            p = low_level_input(netif);
            
            /* no packet could be read, silently ignore this */
            if (p == NULL) continue;
            
            /* entry point to the LwIP stack */
            err = netif->input(p, netif);
            
            if (err != ERR_OK)
            {
                LWIP_DEBUGF(NETIF_DEBUG, ("ethernetif_input: IP input error\n"));
                pbuf_free(p);
            }
            continue;
        }
    }
    
    
}

/**
* Should be called at the beginning of the program to set up the
* network interface. It calls the function low_level_init() to do the
* actual setup of the hardware.
*
* This function should be passed as a parameter to netif_add().
*
* @param netif the lwip network interface structure for this ethernetif
* @return ERR_OK if the loopif is initialized
*         ERR_MEM if private data couldn't be allocated
*         any other err_t on error
*/
err_t ethernetif_init(struct netif *netif)
{
    LWIP_ASSERT("netif != NULL", (netif != NULL));
    
#if LWIP_NETIF_HOSTNAME
    /* Initialize interface hostname */
    netif->hostname = "lwip";
#endif /* LWIP_NETIF_HOSTNAME */
    
    netif->name[0] = IFNAME0;
    netif->name[1] = IFNAME1;
    /* We directly use etharp_output() here to save a function call.
    * You can instead declare your own function an call etharp_output()
    * from it if you have to do some checks before sending (e.g. if link
    * is available...) */
    netif->output = etharp_output;
    netif->linkoutput = low_level_output;
    
    /* initialize the hardware */
    low_level_init(netif);
    
    return ERR_OK;
}

LITE_OS_SEC_TEXT VOID eth_loop(VOID)
{
    
}
void eth_init(void)
{
    
}
